1. Field of the Invention
The present invention relates to an optical subassembly and an optical data link using the optical subassembly.
2. Related Prior Art
The optical assembly provides an optical semiconductor device, such as light-emitting device or light-receiving device, and a sleeve to couple such optical semiconductor device with an optical fiber secured in an optical ferrule. It is necessary for the sleeve to be elastic along radial directions to enhance the performance of the ferrule inserting into and extracting from the sleeve, and to hold the inserted ferrule securely.
A conventional optical assembly, for example, disclosed in Japanese patent issued as 3,314,667, comprises a sleeve, a bush, and a sleeve case. The split sleeve, which is a cylindrical member extending along a prescribed axis, provides a slit. This split sleeve, holding a stub in one end thereof and receiving the ferrule inserted from the other end, makes the optical coupling between the coupling fiber secured in the center of the stub and the other optical fiber secured in the ferrule. The bush is press-fitted into the end of the sleeve where the stub is held. The sleeve case, also a cylindrical member extending along the prescribed axis, covers the sleeve with the bush being press-fitted between the sleeve and the sleeve case.
This split sleeve has superior characteristics for the ferrule inserting into or extracting from the sleeve, due to its radial elastic function, and for the ferrule holding capability due to the bush press-fitted in the one end thereof.
However, the superior characteristic in inserting/extracting of the ferrule and in holding capability are realized in a combination of the split sleeve, the bush, and the sleeve case. Larger number of parts results in the greater variation in the accuracy of the mechanical dimension.